Asymmetric synthesis of cetirizine dihydrochloride
摘要:
Practical route technology for the preparation of (S)-cetirizine.2HCl via diastereoselective organometallic addition to N-tert-butanesulfinyl aldimines is disclosed. (C) 2002 Elsevier Science Ltd. All rights reserved.
addition to enantiomerically enriched (tert-butyl)- and (para-tolyl)sulfinimines. This new in situ protocol produces two new CC bonds. Chiral allylic sulfinamides are obtained in high diastereoselectivity and in good yield. Cleavage of the chiral auxiliary leads to synthetically useful allylic amine building blocks, and facile oxidative degradation of the alkene moiety can be used as an approach toward
在催化性 Cp2ZrCl2 和 H2O 存在下,炔烃的碳铝化得到乙烯基丙烷中间体,其在随后添加到对映体富集的(叔丁基)和(对甲苯基)亚磺酰亚胺中充当亲核试剂。这种新的原位协议产生了两个新的 CC 债券。以高非对映选择性和良好收率获得手性烯丙基亚磺酰胺。手性助剂的裂解导致合成有用的烯丙胺结构单元,烯烃部分的易氧化降解可用作获得氨基酸衍生物和分配绝对构型的方法。
Samarium Diiodide-Induced Asymmetric Synthesis of Optically Pure Unsymmetrical Vicinal Diamines by Reductive Cross-Coupling of Nitrones with <i>N</i>-<i>tert</i>-Butanesulfinyl Imines
作者:Yu-Wu Zhong、Ming-Hua Xu、Guo-Qiang Lin
DOI:10.1021/ol048444d
日期:2004.10.1
[reaction: see text] An efficient method for the preparation of opticallypure unsymmetrical vicinal diamines by the SmI(2)-induced reductive cross-coupling of nitrones with chiral N-tert-butanesulfinyl imines was developed. This is the first successful example of the highly diastereoselective and enantioselective cross-coupling between two different imine species. It provides a straightforward access
A Highly Efficient and Direct Approach for Synthesis of Enantiopure β-Amino Alcohols by Reductive Cross-Coupling of Chiral <i>N</i>-<i>tert</i>-Butanesulfinyl Imines with Aldehydes
作者:Yu-Wu Zhong、Yi-Zhou Dong、Kai Fang、Kenji Izumi、Ming-Hua Xu、Guo-Qiang Lin
DOI:10.1021/ja054401w
日期:2005.8.1
approach for the synthesis of optically pure beta-amino alcohols by the SmI2-induced reductive cross-coupling of chiral N-tert-butanesulfinyl imines with aldehydes was developed. This method allows the preparation of a broad range of chiral beta-amino alcohols, including functionalized ones under mild conditions. It provides a straightforward access to enantiopure beta-amino alcohols that are widely
Auxiliary strategies for the preparation of β-amino alcohols with reductive cross-coupling and a synthesis of (−)-cytoxazone
作者:Xiangjie Lin、Paul A. Bentley、Hexin Xie
DOI:10.1016/j.tetlet.2005.09.002
日期:2005.11
Imine auxiliaries including chiral N-tert-butanesulfinyl imines have been successfully utilized to provide stereochemical control to the reductive cross-coupling of imines with aldehydes or ketones. This methodology has been applied to the synthesis of (−)-cytoxazone.
the highly diastereoselective synthesis of chiral homoallylic amines by Zn-mediated allylation of chiral N-tert-butanesulfinyl imines at room temperature was developed. By simply tuning the reaction conditions, the method allows the achievement of a highly remarkable opposite stereocontrol, affording the desired stereochemical outcome in good yield and with excellent diastereoselectivity (up to 98%